Building for the Long Term: The Durability of Steel Sheet Piles Explained
Steel sheet piles play a vital role in modern construction – forming permanent earth-retaining walls, deep basements, and structural foundations across a wide range of environments. Their strength, versatility, and efficiency make them an ideal choice for both temporary and permanent works.
In most situations, steel sheet piles can be used in an unprotected condition, but understanding how corrosion affects long-term durability is essential for safe and sustainable design.
Understanding Corrosion and Design Approaches
The degree of corrosion, and whether protection is needed, depends largely on the environmental conditions the pile is exposed to – whether it’s in soil, fresh water, or sea water.
There are two main design philosophies when accounting for corrosion:
1️⃣Sacrificial Thickness
This approach accepts that corrosion will occur over time. Engineers allow for a small steel sheet pile ‘sacrificial’ loss of steel thickness in their design calculations to ensure the pile retains sufficient strength throughout its design life.
2️⃣Protective Systems
The second approach involves actively protecting the pile – for example, by painting or galvanising, encasing it in concrete or grout, or applying cathodic protection.
For most basement and retaining wall designs, a combination of sacrificial thickness and sheet pile corrosion protection (coating) is typically the preferred solution.
Estimating Corrosion Rates in Sheet Pile Design
To design for durability, engineers must estimate how much steel will be lost over the intended design life of the structure, as set out in the Eurocode standard: Design of steel structures – Piling.
The table below summarises typical sheet pile corrosion rates, measured as loss of steel thickness in millimetres, for different environmental conditions – as referenced in BS EN 1993-5: Table 4.1 & 4.2
| Corrosion Rates as measured by steel thickness loss over time | |||||
| Design Life | 5 years | 25 years | 50 years | 75 years | 100 years |
| Undisturbed natural soils (sand, clay, etc) | 0.00 mm | 0.30 mm | 0.60 mm | 0.90 mm | 1.20 mm |
| Common fresh water: waterline | 0.15 mm | 0.55 mm | 0.90 mm | 1.15 mm | 1.40 mm |
| Sea water: permanent immersion & intertidal | 0.25 mm | 0.90 mm | 1.75 mm | 2.60 mm | 3.50 mm |
| Sea water: splash & low water zone | 0.55 mm | 1.90 mm | 3.75 mm | 5.60 mm | 7.50 mm |
| Data source: ArcelorMittal – Durability of Steel Piles | |||||
What This Means in Practice
Sheet pile corrosion rates can vary significantly across environments. For example:
- In undisturbed natural soils, section loss after 50 years is typically around 0.6 mm – minimal and easily accommodated in design.
- In contrast, metal sheet piling in the sea water splash zone may experience around 3.75 mm of loss over the same period, due to oxygen-rich, aggressive conditions.
These figures underline why it’s crucial to assess all exposure zones of a pile — soil, waterline, immersion, and splash — relative to the bending and structural demands of the section.
For short-term applications (less than four years) of steel sheet piling retaining walls, corrosion can generally be disregarded. However, for permanent sheet pile walls, corrosion allowances must always be included to ensure long-term performance and safety.
Ivor King: Steel Piles You Can Depend On
At Ivor King, we understand that durability starts with quality materials and expert design. With over 3,000 tonnes of steel sheet piles in stock at our yard, in various profiles, grades, lengths and sheet pile thickness, we’re ready to supply your project – whether you’re looking to hire or buy.
Our experienced team can also advise on the most suitable piling solution for your site conditions – whether temporary cofferdams, or permanent basement retaining walls – ensuring strength, longevity, and value for your investment.
📞 Get in touch today to discuss your project or request a quotation.
The lifespan of steel sheet piles depends on the environment and corrosion conditions. In mild, freshwater or inland soils, steel sheet walls can last over 100 years. In marine or highly corrosive environments, unprotected steel may last 25 to 50 years, but protective coatings or cathodic systems can extend this well beyond 75 years.
Sacrificial thickness is an extra allowance of steel added during design to compensate for expected corrosion over the structure’s service life. It ensures that even after some material loss, the remaining section maintains required strength and stability.
Corrosion protection is typically required when piles are exposed to aggressive conditions, such as saltwater, tidal zones, or industrial soils. Common methods include protective coatings, cathodic protection, or corrosion-resistant steel grades.
Yes. With proper design and protection, steel sheet piles are highly suitable for permanent structures. They offer long-term durability, ease of inspection, and adaptability, especially when coatings or sacrificial thickness are incorporated.
Key standards include EN 1993-5 (Eurocode 3 – Design of Steel Sheet Piling), BS EN ISO 12944 for protective coatings. These define durability requirements, corrosion rates, and design principles for longevity.
Capability coupled with experience
Ivor King has over 50 years of experience in steel sheet piling, we specialise in providing innovative and bespoke piling solutions.
Take a look at the range of Steel Piling Solutions we can design, install, and extract and get in touch with our knowledgeable and friendly team to discuss how we can help. Whatever your piling project, we’re your people.
Sheet Pile Retaining Walls
The quick and easy solution that eliminates the need for temporary earthworks support.
Sheet Pile Basements
Maximise your basement footprint with a cost effective watertight construction solution.
Cofferdams
Allows excavation and construction in otherwise poor working environments
Temporary Sheet Pile Walls
Allowing earthworks to take place, sheet piles can be re-used on project completion
Steel Bearing Pile Foundations
Providing excellent load and resistance and high strength in compression and tension
Ground Anchors
Economical and practical alternative to propping, enabling greater retained heights
Inland Waterways & Marine Piling Solutions
Flood defences and water retention systems, including rivers, canals, harbour and dock wall stabilisations, marinas and reservoirs
Sheet Pile Hire & Sales Our dedicated hire and sales division is on hand to support all your temporary and permanent sheet pile needs
